Resinous composition.



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ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

RESINOI TS COMPOSITION.

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Ito Drawing.-

Specification of Letters Patent.

Application filed February 8, 1912-3.

Serial No. MT/J15.

To all whom it may concern Be it known that 1, MICHAEL J. GALLA- HA'N, a citizen of the United States, residing at Pittsfielol, county of Berkshire, State of Massachusetts, have invented certain new and useful improvements in ltesinous'tlompositions, of which the following is a specilication.

The present invention relates to the synthetic resinous condensation products obtainable by the interaction of a polybasic acid such as phthalic anhydrid With glycerol or other polyhydric alcohol; and its object is to increase the availability of this resin in a fused state for impregnating and other purposes,

As described in my former application, fierial Number "69 {YO l, filed May ll, 1912, glycerol or other polyacid alcohol and l phthalic anhydrid react at an elevated temperature to form a clear, brittle, fusible compound which is soluble in acetone and which upon continued heating is insformed to an infusible, insoluble state. transformation, although hastened by an incretse of tor erature, proceeds even at the melting point of the oroduct. Tlhis factrenders the of cellular or fibrous bodies with. the fused resin diliicult, as the penetration is retarded and when large qua try of sin is ted consider ial api by harder.

in the adult, have CllSCG'VGItDCl that the hardening of the fused resin may be prevented. by the addition to the fused mass of a hydrocarbon of the cyclic or aromatic series, containing; condense nuclei, for example, naphthalei anthracen throne, or other mere, or V i i substitution products its described in my former applicat resin is prepared by slowly heating; about 185 C, a mixture consist" Weight of about two parts of phthalic auhydrid and one part glycerol, until distillation, ceases, and the heating; being; then continued at about 210 C. until small samples when cold are hard and brittle Without stickiness. Heating of he mass is then discontinued. The resulting resin is fusible about 120 C. and soluble in acetone In the preferred form of my invention about 13 to 18 per cent. by Weight of naphthalene is dissolved in the melted resin. The fusing point of the resin is lowered by the dissolved naphthalene to about 90 to 100 C. It follows from this that at higher temperatures the naphthalene increases the fluidity of the melt for any given temperature. A lesser proportion of naphthalene may be used, but it -Wlll have a correspondingly less effect on the melting point of the resin. The naphthalene is kept in solution by maintaining the material heated in a closed tank, preferably by means of steam heat, in this manner the melt is maintained under the vapor pressure of the naphthalene which sublimes from the mass but is melted on the hot ,Walls of the tank and drops back into the fused mass.

F or the purposes of impregnation. it is better that. the fused material. be kept under slight pressure, say air pressure of to 20 pour is per square inch, in order to prevent the sublimed naphthalene from entering pipes and condensing. il hen a charge is to be used for impregnating porous articles of considerable mass, such e ectrical coils Wound With fabrics, or cel lular material such as Wood, or thiclr paper, pressure of to 90 pounds to the e l )3 preferably exerted upon the me ed resin to force the same into the in e articles to be impregnated.

i ecessary for complete i to the pores of the icle to .oe inoregnated may vary fr a few minutes 1' hours and can so easily determined by trial described in my former application, the fusible soluble resin may be converted into an infusible, insoluble state by heating temperature from about 185 C l it is desired to harden the resin thus reduced into clectr'cal coils or the like, coils are baked after impregnation, at auncspheric pressure, for sufficient length of time to drive out toe naphthalene and to complete the above-described prem nary hardening of the resin, The bale temperature may vary from 135 to 150 (3 the temperature being increased to the higher limit toward the end of the baking operation when. the naphthalene has been largely removed and the resin partially hardened. The length of time necessary to complete this first stage of the hardening" of the resin and removal of the solvent will depend upon the size" and shape of the impregnated articles, but, in general, it may be Patented au t as, tort,

said that several hours are required. In some cases the pressure may be less than atmospheric, with advantage. A vacuum may be used to draw out trapped air, especially before the resin is introduced.- The naph" thalene, of course, may be recovered and used over again. a

' As described in my application Serial No. 747,114 filed concurrently herewith, I have found that a second stage of hardening takes 'place when the temperature 1s raised to 190 to 250 C. oreven higher for sevheating is continued and tetrachlor-naphthalene may also be used, but their use introduces difiiculties due to their high boiling points. Anthracene andC1 its substitution products may also be use What I claim as new and desire to secure by Letters Patent of the United States, is 1. The process of preventing the hardenin of a fusible' resin of a polyhydric alco- U holj and 'phthalic anhydrid which consists in maintaining dissolved therein .a hydrocarbon of the aromatic series with condensed nuclei.

2. The'process ofmaintaining a resinous compound saponifiable to yield polyhydric alcohol and a phthalate in a fluid state at an elevated temperature which consists in dissolving therein a hydrocarbon of the aromatic series with condensed nuclei and maintaining said hydrocarbon in solution by compensating pressure.

3. The process of preventing the conversion of a fusible, soluble resin of glycerol and phthalic anhydrid to the infusible, in-

soluble state at an elevated temperature which consists in maintaining naphthalene in contact therewith.

1-. A composition of matter comprising a fusible resinous condensation product saponifiable by alkali to form a phthalate and a polyhydric alcohol and a heavy hydrocarbon of the aromatic series dissolved therein.

5. A. composition of matter comprising naphthalene and a condensation product saponifiable by alkali to yield glycerol and a phthalate of the alkali.

6. A composition of matter comprising a fusible resinous condensation product saponifiable by alkali to form glycerol and a phthalate and about 1318 per cent. of naphthalene.

7. An impregnating composition comprising a solution of hydrocarbon of the cyclic series containing condensed nuclei and a fusible resinous condensation product of a polyhydric alcohol said resinous product being saponifiable and convertible when out of contact with the hydrocarbon to an infusible, insoluble state.

In Witness whereof, I have hereunto set my hand this fifth day of February, 1913.

MICHAEL J. GALLAQHAN.

Witnesses ROBERT F. CHAMBERS, JAMES N. LAWRENCE.

and a polybasic acid, 4 

